Expression of collagen types I, II and III in juvenile angiofibromas

Extracellular matrix components have rarely been the focus of interest in juvenile angiofibroma (JA) studies. Although JAs are known to be collagen-rich tumours, single collagens have not been analysed so far. This investigation aimed to study the expression of the fibrillar collagen types I, II and III in JAs using quantitative RT-PCR (n = 15), Western blot analysis (n = 7) and immunohistochemical staining (n = 9). Nasal mucosa (NM) specimens were used as control tissues. ELISA investigation (n = 3) was performed to determine the concentration of C-terminal propeptide of type I collagen in blood serum before and after JA resection. Quantitative RT-PCR found significantly elevated Col1A1 (p < 0.001), Col1A2 (p < 0.001) and Col3A1 (p < 0.001) mRNA levels in JAs, compared with NM. Western blot analysis and immunohistochemical staining proved that there is a significant collagen type I and III protein expression in JAs. In none out of 3 patients, ELISA investigation found evidence for elevated concentrations of C-terminal propeptide of type I collagen before tumour resection, compared with postsurgical measurements. Results of the findings using quantitative RT-PCR, Western blot analysis and immunohistochemistry determined that type II collagen is practically absent in JAs. Based on these findings, type I and III collagen are confirmed as being major components of the extracellular matrix in JAs. However, our findings are not encouraging as regards the use of C-terminal Col I propeptide as a suitable serum tumour marker. Our findings confirming that collagen type II expression is practically absent in JAs refutes the theory that JAs originate in cartilage tissue.     

The distribution of types I and III collagen and fibronectin in the healing equine tendon

During tissue response to injury the glycoproteins fibronectin and Type III collagen are synthesized in increased amounts. We have studied the distribution of these molecules in the healing tendon at various times after injury by comparison with that of the major constituent of normal tendon, Type I collagen. Immunofluorescent localization demonstrated the presence of fibronectin throughout the tendon within one week after injury. Staining was found in the matrix, both around capillaries and around fibroblast-like cells. Fibronectin was still apparent in the healing tendon at one month after injury, but after a further two months was no longer detectable. Type III collagen was present both in pericellular and matrix locations until three months after injury, and matrix staining was apparent during the entire fourteen-month period under study. Type III collagen was also found throughout the matrix of the contralateral superficial flexor tendon during this period.     

Differential immunohistochemical localization of cytokeratins and collagen types I and III in experimentally-induced cirrhosis

Liver cirrhosis was induced in male Wistar rats by subcutaneous injection (1 ml of 30 g/l) of an aqueous solution of thioacetamide. Using the indirect immunoperoxidase technique, high molecular weight keratins were localized in bile ducts and ductules. Low molecular weight cytokeratins were present in regenerating hepatocytes in active cirrhosis; bile ducts were unstained. These results suggest that cytokeratin staining may be useful in distinguishing bile duct epithelium and hepatocytes in hepatobiliary diseases. Anticollagen type III antibody stained hepatocytes and thin connective tissue fibres, while anticollagen type I antibody stained thicker fibres and some sinusoidal cells but not hepatocytes. Collagens were usually undetectable in normal liver cells. It is suggested, therefore, that hepatocytes may play a major role in collagen type III production which precedes the deposition of collagen type I. By contrast, collagen type I may be produced by fibroblasts and some cells along sinusoids (e.g. perisinusoidal fat-storing cells) after liver injury.     

Distribution of collagen types I, III, and V in pregnant mouse endometrium

Decidualization in mice comprises a deep remodeling of extracellular matrix (ECM) components of the endometrium. In a previous biochemical study we showed that collagen types I and III are present in both pregnant and nonpregnant mouse endometrium, whereas collagen type V is expressed exclusively after the onset of decidualization. The distribution of collagen types in the pregnant mouse endometrium and possible changes of these molecular types in the different regions of the decidua is, however, not known. Using immunofluorescence and confocal microscopy we showed the presence of collagen types I, III, and V in the endometrial stroma of implantation and interimplantation sites from days 5 to 8 of pregnancy in the mouse. Collagen type III was chiefly expressed in the implantation sites and was the only collagen type to be present in the materno-fetal interface on the day of the embryo implantation. However, collagen type I was the predominant collagen in the interimplantation sites. Collagen type V was weakly expressed in the nondecidualized stroma during all periods but was expressed in larger amounts in the decidualized areas on day 7 of pregnancy, simultaneously with the accumulation of thick collagen fibrils in the same region. The highest immunofluorescence labeling for the three types of collagen was observed on day 7 when the antimesometrial decidual tissue achieved its greatest development. These data support previous studies that showed an intense ECM remodeling of the mouse endometrial stroma during the beginning of pregnancy. This outstanding remodeling may be important to stabilize placental anchorage.     

Distributions of types I,II and III collagen by region in the human supraspinatus tendon

Abstract

The mechanical properties of the human supraspinatus tendon (SST) are highly heterogeneous and may reflect an important adaptive response to its complex, multiaxial loading environment. However, these functional properties are associated with a location-dependent structure and composition that have not been fully elucidated. Therefore, the objective of this study was to determine the concentrations of types I, II and III collagen in six distinct regions of the SST and compare changes in collagen concentration across regions with local changes in mechanical properties. We hypothesized that type I collagen content would be high throughout the tendon, type II collagen would be restricted to regions of compressive loading and type III collagen content would be high in regions associated with damage. We further hypothesized that regions of high type III collagen content would correspond to regions with low tensile modulus and a low degree of collagen alignment. Although type III collagen content was not significantly higher in regions that are frequently damaged, all other hypotheses were supported by our results. In particular, type II collagen content was highest near the insertion while type III collagen was inversely correlated with tendon modulus and collagen alignment. The measured increase in type II collagen under the coracoacromial arch provides evidence of adaptation to compressive loading in the SST. Moreover, the structure-function relationship between type III collagen content and tendon mechanics established in this study demonstrates a mechanism for altered mechanical properties in pathological tendons and provides a guideline for identifying therapeutic targets and pathology-specific biomarkers.     

Immunolocalization of fibronectin and collagen types I and III in human fetal parotid and submandibular glands

We examined the distribution of fibronectin and collagen types I and III in human fetuses under a confocal laser scanning microscope using immunohistochemical staining (at 16, 20, 24, 28, 32 weeks' gestation). The collagen types I and III form the collagenous matrix components in the connective tissue of the parotid and submandibular glands. These extracellular matrix components were detected at various stages around the terminal portion and in the capsule-like connective tissue of the parotid and submandibular glands. However, the extracellular matrix components in the connective tissue around the terminal portion had a stronger reaction than those in the capsule-like connective tissue found on the fringe of the terminal portion. The collagen type I of the parotid gland at 16 weeks' gestation had a weaker reaction than that of the submandibular gland. When results of the reaction at other stages and other extracellular matrix components of the two salivary glands were compared, collagen type I appeared as early as at 16 weeks' gestation in either gland. Since collagen type I serves as the core connective tissue, these observations suggest that the formation of connective tissue around the parotid gland occurs before or after 16 weeks' gestation lagging behind that of the submandibular gland.     

Immunohistochemical localization of collagen types I, II, III, and IV in pterygium tissues

Immunohistochemical localization of collagen types I, II, III, and IV in the pterygium was demonstrated by type-specific antibodies. The stromata of pterygium and normal conjunctival tissues contained collagen types I, II, and III, while the normal corneal stroma showed collagen types I and III but not collagen type II. Collagen type IV was located in the epithelial and capillary endothelial basement membranes of pterygium and normal conjunctival tissues. These results suggest that collagens in pterygial tissues are derived from those in the conjunctival tissues.     

Immunomorphological study of fibronectin and collagen types I, III, IV and V in the myocardium in cardiosclerosis

Fibronectin and collagen, types I, III, IV and V, in the granulation tissue replacing the myocardial infarction, in the focal and diffuse cardiosclerosis were studied by means of the immunofluorescent method. The extracellular matrix in the granulation tissue contained fibronectin and collagen of the above types. Intracellular fibronectin was also found in the necrotized cardiomyocytes. Fibronectin and collagen of type IV were not detected in the postinfarction scars. The extracellular matrix consisted mainly of collagen, types III and V. Fibronectin and collagen, types I, III and V, are observed in the connective tissue in diffuse cardiosclerosis in the presence of the coronary arteries stenosis. No prevalence of the collagen of any type was found.     

Detection of fibronectin and collagen types I, III, IV and V in semithin sections of the human aorta

Localization of fibronectin and types I, III, IV and V collagen was investigated in semithin sections of fibrous atherosclerotic plaques and apparently normal intima of human aorta. The effect of different techniques of fixation and processing of the sections on immunostaining under peroxidase-antiperoxidase techniques have been examined. The tissue fixation in paraformaldehyde solution, removing the resin with sodium ethoxide and enzymatic pronase digestion of the sections resulted in successful specific staining of the antigens. It was found that some cells in fibrous plaques formed a cap of multiple layers of dense connective tissue containing fibronectin and type III, IV and V collagen in the absence of collagen type I.     

Calcium alginate enhances wound healing by up-regulating the ratio of collagen types I/III in diabetic rats

Calcium alginate has been proved to favor the skin ulcer healing and collagen synthesis was a critical factor for the wound closure. The present study was to elucidate the mechanism of calcium alginate on the diabetes skin ulceration. Calcium alginate dressing was applied daily on the full-thickness exercising wound created on the back of diabetic rat model as Alg-group (n=6), and the vaseline dressing was used as control (n=6). Rats were respectively sacrificed and the wound tissues were removed and used for the evaluation of various biochemical analysis contained collagen (type I and III) by Western blotting and hydroxyproline level changes by ELISA assay at 3 d, 7 d and 14 d after wounding. The expression of skin collagen I in Alg-group was enhanced from day 3 (0.66±0.25 vs. 0.42±0.09, P<0.05) to day 14 (1.09±0.14 vs. 0.78±0.16, P<0.05). However, no significant difference of collagen III expression was found between two groups during wound healing (P>0.05). And the ratio of collagen I/III in Alg-group was greater than that of Vas-group at day 7 (1.07±0.31 vs. 0.77±0.11, P<0.05) and 14 (1.18±0.30 vs. 0.83±0.14, P<0.05). The hydroxyproline level in skin homogenate of Alg-group was higher than that of Vas-group from day 3 (30.29±0.92 ng/ml vs. 27.52±0.83 ng/ml, P<0.05) to day 14 (89.58±4.97 ng/ml vs. 79.30±4.42 ng/ml, P<0.05). Calcium alginate accelerates the process of wound healing through improving type I collagen synthesis and increasing ratio of collagen I/III in diabetic rats.     

Localization of types I, II and III collagen and glycosaminoglycans in the mandibular condyle of growing monkeys: an immunohistochemical study

 In order to analyse the regional and age-related variations of primate condyles, immunohistochemical techniques were used to examine the localization of types I, II and III collagen and a variety of glycosaminoglycans in distinct anteroposterior regions of the mandibular condyle of two growing female rhesus monkeys (Macaca mulatta). In the juvenile monkey staining for types I and III collagen was weak in the fibrous tissue layer, intense in the pre-cartilaginous tissue layer and faint in the cartilaginous tissue layer; staining was significantly more intense in the posterosuperior and posterior regions than in the anterior region. Similarly, staining for cartilage-characteristic extracellular matrices, including type II collagen and keratan sulfate, was intense in the cartilaginous tissue layer of the posterior condyle. In contrast, in the late-adolescent monkey staining for the extracellular matrices was more intense in the anterior half of the condyle (i.e. from the anterior to the posterosuperior region) than in the posterior region, and most intense in the posterosuperior region. The results demonstrate that marked regional differences exist in the phenotypic expression of the extracellular matrices in the mandibular condyles of growing monkeys and that these differences vary between different developmental stages. The variations probably reflect the predominance of competing growth and articulatory functions in the mandibular condyles. Accepted: 19 July 1996     

Immunolocalization of collagen types I, III and IV, elastin and fibronectin within the heart of normal and copper-deficient rats

Collagen types I, III and IV, fibronectin and elastin were detected by immunohistochemistry in the normal and copper-deficient rat heart. All rats maintained on a copper-deficient diet for at least 6 weeks were found to have areas of abnormal distribution of these connective tissue components within the endo- and perimysium although the normal appearance observed in control animals prevailed. It appeared that the proliferation of the fibrillar collagens and fibronectin was associated with fibrosis and scar tissue formation. In contrast, the fragmented and disorganized appearance of the myocyte basement membrane and the endomysial elastin did not seem to be associated with the fibrotic process and may be an early indication of copper deficiency. The vascular system of the copper-deficient hearts appeared normal. These results are discussed with reference to the functional and mechanical abnormalities that occur in copper-deficient animals.     

Changes in histoanatomical distribution of types I, III and V collagen promote adaptative remodeling in posterior tibial tendon rupture

INTRODUCTION: Posterior tibial tendon dysfunction is a common cause of adult flat foot deformity, and its etiology is unknown. PURPOSE: In this study, we characterized the morphologic pattern and distribution of types I, III and V collagen in posterior tibial tendon dysfunction. METHOD: Tendon samples from patients with and without posterior tibial tendon dysfunction were stained by immunofluorescence using antibodies against types I, III and V collagen. RESULTS: Control samples showed that type V deposited near the vessels only, while surgically obtained specimens displayed type V collagen surrounding other types of collagen fibers in thicker adventitial layers. Type III collagen levels were also increased in pathological specimens. On the other hand, amounts of collagen type I, which represents 95% of the total collagen amount in normal tendon, were decreased in pathological specimens. CONCLUSION: Fibrillogenesis in posterior tibial tendon dysfunction is altered due to higher expression of types III and V collagen and a decreased amount of collagen type I, which renders the originating fibrils structurally less resistant to mechanical forces.     

Distribution of collagen types I and III and basal lamina in human gastric carcinoma: An immunohistochemical and electron microscopic study

Summary Collagen types I and III were examined immunohistochemically in 32 cases of gastric carcinoma classified as poorly differentiated adenocarcinoma with scirrhous stroma, well differentiated adenocarcinoma with intermediate stroma, or poorly differentiated adenocarcinoma with medullary stroma. In the stroma of scirrhous carcinoma, types I and III collagens were distributed abundantly in fibrillar or granular patterns with little difference in the intensity of staining. In well differentiated adenocarcinoma, type I collagen was diffusely distributed in the stroma with type III collagen distributed sparsely. In poorly differentiated adenocarcinoma with medullary stroma, the two types of collagen were only found around capillaries, constituting the tumor interstitium. Electron microscopic examination of scirrhous carcinoma showed tumor cells partially covered with fibroblasts, and discontinuous basal lamina, collagen fibers and microfibrils present between tumor cells and fibroblasts. In well differentiated carcinoma, tumor cells were surrounded by fibroblasts, and well developed basal lamina was observed beneath the tumor cells. In poorly differentiated carcinoma with medullary stroma, the stroma consisted of capillaries and very few fibroblasts with discontinuous basal lamina occasionally being present between tumor cells and fibroblasts.     

Age-related changes in the microarchitecture of collagen fibrils in the articular disc of the rat temporomandibular joint

The microarchitecture of collagen fibrils in the articular disc of the temporomandibular joint (TMJ) plays an important role in dissipating the mechanical load during jaw movement. However, little information is available on its adaptations to the biomechanical environment during development. To address this issue, we analyzed the diameter of collagen fibrils of the articular disc of the rat TMJ with quantitative ultrastructural analysis during postnatal development. The mean diameter of the collagen fibrils significantly increased and the arrangement of the collagen fiber networks became compact during development. Articular discs of suckling rat pups were composed of thin, uniformly sized collagen fibrils (range: 30-60 nm, peak: 40-50 nm). At the age of 4 weeks, thicker collagen fibrils began to appear in articular discs, shortly after weaning (range: 20-70 nm, peak: 40-50 nm). In articular discs of adult rats, collagen fibrils varied widely in diameter, with thick fibrils predominating (range: 10-120 nm, peak: 40-70 nm). These age-related changes in the microarchitecture of collagen fibrils in articular discs may reflect changes in their biomechanical environment during development.     

Localization of collagen types I, III, IV and V, fibronectin and laminin in human arteries by the indirect immunofluorescence method

The distribution of types I, III, IV and V collagen and of the glycoproteins fibronectin and laminin in sections of human aortas, arteries and atherosclerotic plaques were studied using monospecific antibodies and indirect fluorescence microscopy. Types IV and V collagen and laminin were present in a narrow zone, representing the basement membrane, apposed to the endothelial layers of all these tissues. Types I and III collagen and fibronectin were located in the interstitial spaces of the intima and the media of blood vessels walls, whereas types IV and V collagen and laminin were found in the basement membranes underlying smooth muscle cells in these areas. Two types of atherosclerotic plaques were observed. Lipid-rich plaques contained less collagen and reduced amounts of the glycoproteins. Fibrous plaques consisted of regions deficient in types I and III collagen and collagen-rich regions with elevated levels of these two collagens as well as more fibronectin. The collagen-rich regions of fibrous plaques contained, however, little type IV and type V collagen and little of the glycoproteins laminin and fibronectin. This may be due to the reduced number of cells involved in the biosynthesis of these basement membrane proteins.